ISC 2026 Physics Improvement Examination Question Paper for Class 12

About this paper

This is ISC Class 12 Physics Paper 1 (Theory) from CISCE's 2026 Improvement Examination (paper code 861A, printed as 1226-861A-I.E.). It carries 70 marks, runs for three hours plus fifteen minutes of reading time, and has 20 compulsory questions in four sections, with internal choices in two questions each in Sections B, C and D. Section A has seven multiple-choice items, opening with the potential energy of a charged honeybee and a pollen grain, plus seven very short answers. Section B includes a question on the radiation used in a cash counting machine, and Section D ends with a passage about a panel discussion on atomic models, fission and fusion. A list of useful constants is printed at the end, and a simple scientific calculator is allowed.

Exam

ISC Class 12

Subject

Physics

Year

2026

Paper code

861A

Maximum marks

70

Time allowed

3 hours + 15 min reading

Questions

20

Pages

12

Answers included

No, questions only

Paper pattern

• Section A

  14 marks

  Question 1 with 14 one-mark parts: 7 multiple-choice (one assertion–reason) and 7 very short answers

• Section B

  14 marks

  Questions 2–8, two marks each; internal choice in two questions

• Section C

  27 marks

  Questions 9–17, three marks each; internal choice in two questions

• Section D

  15 marks

  Questions 18–20, five marks each, ending with a passage-based question on atomic and nuclear physics; internal choice in two questions

Topics covered

• Electrostatic potential and electric dipole
• Capacitors
• Current electricity, Kirchhoff's laws and metre bridge
• Potentiometer
• Moving charges, Ampère's law and galvanometers
• Electromagnetic induction and alternating current
• Electromagnetic waves
• Lenses and optical instruments
• Interference and diffraction
• Photoelectric effect
• Atoms and nuclei
• Semiconductor diodes

Questions from this paper

1. You are provided with three identical capacitors, each of capacitance 12 μF. Calculate the range (minimum to maximum) of capacitance that can be obtained using all three of them.
2. Two bulbs B₁ (100 W, 220 V) and B₂ (200 W, 220 V) are connected in series to a 220 V supply. Perform the necessary calculations to find out which bulb glows brighter.
3. Calculate the position of an object placed in front of a convex lens of focal length 5 cm to obtain an image that is upright and magnified four times.
4. A compound microscope has a magnifying power of 30 and its eyepiece has a focal length of 5 cm. If the final image is formed at the least distance of distinct vision (D = 25 cm), find the magnification produced by the objective lens.
5. Why does violet light produce a narrower diffraction pattern than red light in a Fraunhofer single slit experiment?
6. According to Bohr, how much energy is emitted by a hydrogen atom when its electron goes from the third orbit to the second, if the total energy in the nth orbit is Eₙ = −13.6/n² eV?